DORGR2(l) ) DORGR2(l)
DORGR2 - generate an m by n real matrix Q with orthonormal rows,
SUBROUTINE DORGR2( M, N, K, A, LDA, TAU, WORK, INFO )
INTEGER INFO, K, LDA, M, N
DOUBLE PRECISION A( LDA, * ), TAU( * ), WORK( * )
DORGR2 generates an m by n real matrix Q with orthonormal rows, which is defined as the
last m rows of a product of k elementary reflectors of order n
Q = H(1) H(2) . . . H(k)
as returned by DGERQF.
M (input) INTEGER
The number of rows of the matrix Q. M >= 0.
N (input) INTEGER
The number of columns of the matrix Q. N >= M.
K (input) INTEGER
The number of elementary reflectors whose product defines the matrix Q. M >= K >=
A (input/output) DOUBLE PRECISION array, dimension (LDA,N)
On entry, the (m-k+i)-th row must contain the vector which defines the elementary
reflector H(i), for i = 1,2,...,k, as returned by DGERQF in the last k rows of its
array argument A. On exit, the m by n matrix Q.
LDA (input) INTEGER
The first dimension of the array A. LDA >= max(1,M).
TAU (input) DOUBLE PRECISION array, dimension (K)
TAU(i) must contain the scalar factor of the elementary reflector H(i), as
returned by DGERQF.
WORK (workspace) DOUBLE PRECISION array, dimension (M)
INFO (output) INTEGER
= 0: successful exit
< 0: if INFO = -i, the i-th argument has an illegal value
LAPACK version 3.0 15 June 2000 DORGR2(l)